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S. S. ALLIN. COMBINED DOOR OHEOKA'ND SPRING.

110.505,744. O Patented sep1;. 26`,1893.

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UNrrnD STAT-ns SAMUEL SEALY ALLIN,

vParisian nunon.

OF LONDON, VENGrYLANDQv sPEcmIcArroN forming par@ `er Letters Patent No.565,744, dated september' senses,

Appncaitn inea May 31, 1892. seria No. 435,093. da maar retoma inEngland April so, 1391.110. 71497,@1 renew 22,1892,^No. 3,429; in FranceMarch 8, 1892, No. 219,963; in Germany March 11, 1892, No. 66,127; inBelgium March 16,` 1892, No.- 98,831; in Switzerland April 23, 1892, No.4,913 in Austria-Hungary August 28, 1892, No. 21,767 and No.

36,284; in Italy January 7, 1893, LXV. 168, enclin CanadaJune26,1893,No.43,379.

To all whom it `may concern/.j i

Beit known that I, SAMUEL SEALY ALLIN, a citizen of England, residing at52 Woodstock Road, Bedford Park, Ohiswick, London, England, haveinvented certain new and useful Improvements in Check-Springs forDoors,(for which I havecbtained Letters Patent in Great Britain April 30,1891, No. 7,497, and February 22, 1892, No. 3,429; in Austria-HungaryAugust 28, 1892, No. 21,767 and No. 36,284; in Canada June 26, 1893, No.43,379; in France March 8, 1892, No. 219,963; in Germany March 11, 1892,No. 66,127; in ItalyJanuary', 1893, Vol. LXV, 168;'in Belgium March 16,1892,No. 98,831, and in Switzerland April 23, 1892, No. 4,913,) of whichthe follow-` ing is a specication.`

My invention relates` to check springs for doors of the kind .wherein apiston linked to the door is urged by a spring in a direction to closethe door, but is resisted by duid in a cylinder so as to effect theclosing gradually without shock. Check springs operating in this way areusually visible on the door or door frame, where they are objectionableas being unsightly.

One object of my invention is to avoid this objection by Iitting thecheck spring in the door jamb in a position where it is not seen.

I provide also means of holding the door open and of regulating thefluid resistance so that the door maybe made to close more or lessslowly, and yet to make the lastlpart of its movement with sufcientforce to engage the latch.

1 shall describe the construction of the check spring which I adopt,along with certain modifications to suitspecial conditions, referring tothe accompanying drawings.

Figure 1 is a longitudinal `section andrFig. 2 an end View of the checkspring adapted for air resistance. Fig. 3 is a .longitudinal section andFig. 4 is a transverse section of the cylinder adapted for theresistance of a Fig. 5 is a part section showing the spring checkapplied to a door swinging both ways.

Referring to Fig. 1, A is a cylinder fixed in the jamb D to which ishung a door by the `mouth of the cylinder A projects inward a tube Ilforming a guide for the piston stem I which is connected by a link F` toa pin b fixed in a recess of the door hinge. When a position such asisindicated by the dotted 'lineffnearly'in line with the axis of thehinge, the door remains open. The position of the pini?) and the lengthof the link E are such that the door, when it begins to close, issubject to comparatively little spring force, the force acting at adisadvantageous leverage.

1 To thesteml is attached a piston consisting of two parts, the one M ofconical form externally, "it ting into the other internally coned part Nwhich is of leather or such like flexible material and is free to moveon the stem but is urged toward M by a light spring Q bearing on awasher q the force of this spring being adjustable by screwing more orless forward a nut R. This nut is preferably made of the same diameteras the cylinder A so that it serves to guide the piston stem.

Between the part M of the piston and the cover C of the cylinder isplaced a helical spring J under sufficient strain to effect the closingof the door. When the door is opened it is resisted by this spring butthe part M of the piston being withdrawn from N, :air can freely passinto the space ofthe cylinder behind N. On letting go the door thespring J presses the part M of the piston into the part N expanding thelip-of N so that it lits closely to the internalsurface of the cylinderA and the air imprisoned behind it becomes compressed, retarding themovement of the piston inward and so retarding the closing of the door.In order to regulate this retardation by allowing more or less air topass the piston I make a hole through M and fit it with a screw plug Twhich is grooved or flattened on the side and has a long stem entering atube U havinga headW notched so Vthat it can be turned by a' screwdriver. The stem of the plug T and the tube U being of section notcircular, by applying a screwdriver to turn the tubeUthe plug can bemore or less unscrewed so as to allow passage of air alongits hinge B.`Fromlthe plate C which covers the the door is so faropenedthat the linkF takes r cylinderA behind the piston.

flat side or groove, or it can be screwed home with a packing washerunderits head to close completely the passage through the piston. Thescrew-driver head W may be removed leaving the tube U open at the endand the stem of the screw T may bc so far elongated as to project beyondthe end ot the cylinder when the door is opened so that it can be turnedby a screw-driver or key.

Though it is desirable to retard the door during the greater part of itsclosing movement it is generally desirable also to have the last part ofthe movement unimpeded, so that the door can close with sufficient forceto latch itself. In order to provide for this I make the end part of thecylinder A from some point such as X of a little larger diameter thanthe rest of t-he cylinder, so that when the piston moves along thisenlarged part, air can find its way from behind it, thus relieving thepressure acting against the piston. A like result can be attained byfitting in the bottom of the cylinder a plug valve n which is usuallykept closed by a springo but which is opened allowing escape of air whenthe stem of the piston meets the stemp ofthe plug n. By screwing thestem p more or less forward the escape of air can be made to take placesooner or later during the closing of the door.

When liquid such as glycerine is used to retard the piston, I provide asshown in Figs. 3 and 4t a reservoir for the liquid under the cylinder Aand communicating in front with the cylinder by a hole Z which is alwaysopen, and behind by a hinged valve l) having a small hole through it,this valve being situated behind a partition d which extends nearly tothe bottom of the reservoir Y. As the piston is drawn forward in openingthe door, liquid can iiow freely from the partition d, past the valve bwhich is open into the But when the piston moves back in closing thedoor, the valve b closes and the liquid can only pass through the smallhole in the valve, the movement of the piston being thus checked. As thepiston approaches the end of its instroke the nut R meeting theprojecting end of the valve b opens the valve, thus relieving theresisting pressure and allowing the door to make the last part of itsclosing movement with sufficient freedom to become latched.

Such liquid as may pass the piston flows back into the reservoir Ythrough the hole Z.

Having thus described the nature of my invention and the best means Iknow for carrying the same into practical effect, I claim- 1. In a doorcheck and closer, the combination with a cylinder of a piston working insaid cylinder and having an opening T therein, a screw plug iitting saidopening to regulate leakage through the piston, and an extensible shaftconnected with said screw plug and extending to the exterior of thecylinder, whereby said plug may be turned exteriorly of the cylinder,substantially as described.

2. In a door check, and closer, the combination with a cylinder, and apiston working4 therein, of a pin located in a recess ot the door, and arod connecting the pin with the piston rod and having a bend to clearthe hinge-knuckle when the door is opened to right angles, theconstruction being such that when the door is opened the line ofconnection formed by the bent connecting rod passes through the hingepin and the door is held open, substantially as described.

3. In a door check and closer, the combination with a cylinder of apiston constructed in two parts, one of said parts being rigidly securedto the piston rod and the other of said parts being movable on said rod,substantially as described.

4. In a door check and closer, the combination with a cylinder, of apiston constructed in two parts one of which parts is exteriorly conicaland rigid with the piston rod, and the other of which parts isinteriorly conical and movable upon said rod, substantially asdescribed,

5. In a door check and closer, the combination with a cylinder, of apiston constructed in two parts, one ot' said .parts being rigid withthe piston rod and the other of said parts movable on said piston rod,and means for regulating the leakage through 011e of the parts of saidpiston, substantially as described.

6. In a door check and closer, the combination with a cylinder, and apiston working therein and having a stem, of a spring-valve located inthe bottom ot' the cylinder, and an adjustable screw stem operated bythe stem of the piston to open said valve for the escape of air and thesudden closing of the door at this time, substantially as described.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, this 22d day of April, A. D.1892.

SAMUEL SEALY ALLIN.

Witnesses:

. OLIVER IMRAY, Chartered Patent Agent, 28 Southampton Buildings,London, l/V. O.

JN0. P. M. MILLARD, Clerk to llfessrs. Abel d: [n1/ray, ConsultingEngineers and Patent Agents, 28 Southdanpton Buildings, London, W. C.

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